Conventionally, sterile parenteral dosage forms of solutions or dispersions of biologically compatible liquids with or without medicament for intravenous, intramuscular, subcutaneous or similar routes of administration are placed in sterile injectable form by withdrawing sterile material from a bottle with a sterile hypodermic syringe and needle just prior to administration or, in the case of disposable hypodermic syringes, a presterilized parenteral solution or dispersion is prepared and filled into the sterile syringe barrel for subsequent use with a syringe holder dispensing device. Although aspectic manufacturing of prefilled disposable syringes is possible, it does not offer the same confidence as terminal sterilization.
Terminal sterilization of parenteral solutions and disposable syringes would be accomplished after filling the syringe, as the final production step. However, attempts to sterilize parenteral solutions contained within a disposable syringe employing conventional sterilization techniques results in loss of solution by expulsion of the plunger, displacement of the cannula cover and/or distortion of the secondary packaging container as a consequence of internal pressure created by liquid and gas (headspace) expansion.